Douglas Queen, 49, was last seen on Monday at around 8:30 a.m. in the area of College Street and Brock Avenue.
Queen is white, six foot, five inches tall with grey shaved hair and a thin build. He was last seen wearing a brown golf sweater, beige pants and a blue jacket.
Police are concerned for his safety and have set up a command post at Humber Bay Park near Lakeshore Blvd. West and Park Lawn Road.
CBC News has learned that's where Queen's car was found.
Anyone with information is asked to contact 11 Division at 416-808-1100, or Crime Stoppers at 416-222-TIPS or 222tips.com.